William loeitljer



W. LOEFFLER.

CHAIR IRON.

APPLICATION FILED MAY I6. 1918.

Patented Sept. 23, 1919.

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WITNESSES.

ATTORNEY.

. .WILLiAM tonrrnnit or sna aorsiuv, wxsoonsm,

i t e wae v Be it'knownthat I, WVILLIAM Lemmas, a citizen of the United States, and resident of Sheboygan, Sheboygan county, Wisconsin, have invented new and usefulImprovements in Chair-Ironsyof which the followingis a description, reference being-had to the accompanyingdrawings, which are a part of this specification. 1 This inventionhasiforits object to provide a chair iron which will permit the chair to turn in its swivel movements without affecting its adjustmentjas to height, but which upon operation of asuitablelpartwill be capable'of vertical adjustment by reason of such swivel movements. 1

Another -object of the invention is to perfect details of construction of a chair iron having these characteristics. 1 l

With the aboveand otherifobjects' in view the invention oonsists in the chair iron as herein claimed and all equivalents.

Referring to the accompanying drawings in which like characters of reference indi cate the same parts in different views:

Figure 1 is a vertical sectional view of a chair iron constructed in accordance with this invention;

Fig. 2 is a plan view thereof; 7

'Fig. 3 is a sectional plan view of the crab showing the cams; and,

Fig. 4 is a front view with the cam lever sectioned.

In these drawingslO indicates the hub, preferably with an extension 11 to lengthen the bore which is provided with screw threads 12. The chair spider 13 of usual construction is pivotally mounted on the ears 14 of the fork 15, known as a crab, on the upper end of a spindle 16. The usual stop lugs 17 on the crab playing in slots 18 of the spider limit the tilting movements of the chair seat, while a compression spring 19 serves to hold the chair seat in its normal position in the ordinary manner.

The spindle 16 is not provided with screw threads but bears at its lower end against a screw member 20 which is provided with screw threads meshing with the threads 12 of the bore of the hub. The screw member 20 takes the end thrust of spindle 16 to support the weight of the chair seat and its load. As the friction of the intermeshing screw threads is greater than the friction of this end thrust bearing, turning or swivel movements of the chair seat will have no ef- Specification of icttei's llatent. iP gttented Sept, 1919, A pplicatiolifiled may. 16, 191s. Serial No. 234,899.

feet on the screw member, which willremain' .111 1ts position in the bore of the hub to maintain the chair seat at a predetermined height. Anafitifriction bearing such as a washer 21 maybe introduced between the screw member 20 and the end of the 'spindle.

bolt 22passes centrally through the spindle and the screw member with ahead 23 on its upper end and a pair of jam nuts 24: threaded on its lower end. A cam lever 25"is loosely mounted on the bolt 22 and has oppositely positionedcam faces bearing on corresponding cam surfaces 26 on the crab. By" swinging the cam lever 25 it may be raised or lowered by the action of these cams for raising or lowering the bolt22 and cons'equently clamping the screw member and spindle together or releasing them. y

In the normal-or lowermost position of the cam lever 25 the bolt 22 exerts no clamping action and the chair seat is freeto turn without varying its vertical adjustment.

When it is desireclto raise'or lower thechair seat the cam lever 25 is swung to a position shown in dotted lines in Fig. 2 where its cam action causes the bolt 22 to clamp the screw member 20 to the spindle 16 and then by turning the seat the screw member is also compelled to turn and thread its way to a new position in the hub where it will remain when the clamping lever is returned to its normal position to retainthe seat at the height to which it is adjusted. The extension on the hub affords a long range 01 adjustment for the screw member with ample lateral support for the spindle in the bore of the hub.

The chair iron of this invention is very simple in its construction and is strong and durable and inexpensive to manufacture.

I desire it to be understood that this invention is not limited to any specific form or arrangement of parts except in so far as such limitations are specified in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. A chair iron, comprising an internally threaded hub member, a chair supporting spindle rotatably mounted in the hub member without having threaded engagement therewith, a screw member threaded in the hub member with the spindle bearing thereon, and means passing through the spindle for clamping the screw member and the spindle together for turning the screw memher in the hub member on the turning of the spmdle. v

2. A chair 1ron, comprising a hub member having a screw threaded bore, a screw member threaded in the hub memberfa seat supporting spindle rotatably mounted in the bore of the hub member and bearing 'on the screw member, and; cam means carried by the spindle for clamping the screw member and the spindle together.

3. A chair iron, comprising a hub member provided with a screw threaded bore, a seat supporting spindle journaled within the threaded borerof the hub member without threaded engagement therewith, a screw member threaded in the bore of the hub member and forming an end thrust bearing for the spindle, a clamping bolt passing through the screw member and the. spindle, and means for tightening the clamping bolt for clamping the screw member to the spindle for compelling it to turn therewith.

4. A chair iron, comprising a hub member with a screw threaded bore, a screw member threaded therein, a seat supporting spindle journaled within the threaded bore of the hub member and having an end thrust bearing on the screw member, a bolt passing through the screw member and the spindle, and a cam lever loosely mounted on Copies of this patent may beobtai nerl for the bolt and engaging the head thereof and provided with cam surfaces cooperating with'cam surfaces on the end of the spindle threaded nut, a screwengagedin the threadsofthe nut, a tubularv chair spindle journaled within the nut and resting on the screw, and means passing. through the spindle for connecting the spindle withgthe screw to compel the two to rotate together for adjusting, the height of the spindlein the nut and thereby adjusting the heightofthe chair. H V

In testimony whereof I afiix myusignature in presence of two witnesses. V

lVILLIAM LOEFFLER.

Witnesses: I v

WILLrAM Lonr'rLER, FRANK W. MARGENAU. V

five cents each, by addressing the Commissioner of Patents. Vt'aehingtou, 10.; C. i 

